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From: Michael Wu <michael.wu@kneron.us>
To: Jarkko Nikula <jarkko.nikula@linux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Jan Dabros <jsd@semihalf.com>,
	linux-i2c@vger.kernel.org
Cc: Andi Shyti <andi.shyti@kernel.org>,
	Morgan Chang <morgan.chang@kneron.us>,
	linux-kernel@vger.kernel.org, Michael Wu <michael.wu@kneron.us>
Subject: [PATCH 0/2] Compute HS HCNT and LCNT based on HW parameters
Date: Wed, 25 Sep 2024 16:04:29 +0800	[thread overview]
Message-ID: <20240925080432.186408-1-michael.wu@kneron.us> (raw)

In commit 35eba185fd1a ("i2c: designware: Calculate SCL timing
parameters for High Speed Mode") hs_hcnt and hs_lcnt are computed based
on fixed tHIGH = 160 and tLOW = 320. However, this fixed values only
applies to the combination of hardware parameters "IC_CAP_LOADING = 400pF"
and "IC_FREQ_OPTIMIZATION = 1". Outside of this combination, SCL frequency
may not reach 3.4 MHz if hs_hcnt and hs_lcnt are both computed using these
two fixed values.

Since there are no any registers controlling these two hardware
parameters, their values ​​can only be noted through the device tree.

Michael Wu (2):
  i2c: designware: determine HS tHIGH and tLOW based on HW paramters
  dt-bindings: i2c: snps,designware-i2c: add bus-loading and
    clk-freq-optimized

 .../bindings/i2c/snps,designware-i2c.yaml     | 19 +++++++++++++++
 drivers/i2c/busses/i2c-designware-common.c    | 16 +++++++++++++
 drivers/i2c/busses/i2c-designware-core.h      |  8 +++++++
 drivers/i2c/busses/i2c-designware-master.c    | 24 +++++++++++++++++--
 drivers/i2c/busses/i2c-designware-platdrv.c   |  2 ++
 5 files changed, 67 insertions(+), 2 deletions(-)

-- 
2.43.0


             reply	other threads:[~2024-09-25  8:04 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-25  8:04 Michael Wu [this message]
2024-09-25  8:04 ` [PATCH 1/2] i2c: designware: determine HS tHIGH and tLOW based on HW paramters Michael Wu
2024-09-25  9:16   ` Andy Shevchenko
2024-09-25  9:21     ` Andy Shevchenko
2024-09-26  8:45       ` Michael Wu
2024-09-26 12:18         ` Andy Shevchenko
2024-09-26 13:50           ` Krzysztof Kozlowski
2024-09-26 14:09             ` Andy Shevchenko
2024-09-25 10:58   ` Jarkko Nikula
2024-09-25 11:02     ` Andy Shevchenko
2024-09-26  9:11     ` Michael Wu
2024-09-25 11:33   ` Krzysztof Kozlowski
2024-09-27 13:41   ` kernel test robot
2024-09-25  8:04 ` [PATCH 2/2] dt-bindings: i2c: snps,designware-i2c: add bus-loading and clk-freq-optimized Michael Wu
2024-09-25 11:32   ` Krzysztof Kozlowski

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